Information disclosure - CVE-2017-17689

CSH
CYBERSECURITY HELP
Sign In REGISTER
 
Main Vulnerability Database Vulnerabilities #VU12649

Information disclosure - CVE-2017-17689

Published: May 15, 2018 / Updated: August 27, 2020


Vulnerability identifier: #VU12649
CSH Severity: Low
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2017-17689
CWE-ID: CWE-200
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to obtain potentially sensitive information.

The vulnerability exists due to improper access controls. A remote attacker with access to a target user's S/MIME encrypted email message can exploit a property of Cipher Feedback Mode (CFB) by modifying known plaintext blocks (such as MIME headers). When the target user decrypts and views the modified email message, the target user's mail client will parse the resulting modified HTML content and disclose the original plaintext to a remote URL.

This exploit is the "CFB gadget" attack method of the vulnerability referred to as "EFAIL".


Affected software

Fedora
Apple iOS
SUSE Linux
Ubuntu
openSUSE Leap
thunderbird-enigmail
kdepim (Ubuntu package)
kmail (Ubuntu package)
kf5-messagelib (Ubuntu package)
Mozilla Thunderbird

How to mitigate CVE-2017-17689

Cybersecurity Help is currently unaware of any solutions addressing the vulnerability.

thunderbird-enigmail - addressed in versions 2.0.4-1.el7, 2.0.4-1.fc26, 2.0.4-1.fc27, 2.0.4-1.fc28, 2.0.6-1.el7
kdepim (Ubuntu package) - addressed in versions 4:4.13.3-0ubuntu0.2+esm1, 4:15.12.3-0ubuntu1.1+esm1
kmail (Ubuntu package) - addressed in versions 4:17.12.3-0ubuntu1+esm1, 4:19.12.3-0ubuntu1+esm1
kf5-messagelib (Ubuntu package) - update to 4:17.12.3-0ubuntu3+esm1

External References

Related Security Bulletins